The present invention relates to wireless communications systems, and more particularly to apparatus and a method for dynamically reallocating central resources and remote transceivers to better handle peak traffic loads in a wireless telephone system where the remote transceivers carry telephony signals between wireless telephones and a central transceiver via a broadband distribution network.
The prior art teaches the use of existing cable television network cables to carry telephony signals between a telephone network and remote transceiver sites in defined cells or sectors. The transceivers are used to establish wireless telephony communication links with wireless telephones that are operating within an area covered by each remote transceiver. To increase the number of wireless telephone subscribers that can use the wireless telephone system it has been suggested to decrease the size and operational range of each cell or sector, and to increase the number of cells or sectors required to provide wireless telephone service to a given area. Having cells or sectors of decreased size permits greater reuse of the limited number of frequency channels allocated for wireless telephone service because other cells or sectors located at a closer range can reuse the same frequency channels for additional calls without signal interference. The advantages of reducing cell or sector size to increase the call carrying capacity of the wireless telephone network is offset by the requirement for additional remote transceivers for the additional cells. This offset is minimized by utilizing an existing broadband distribution network to provide the communications path between remote transceivers in each of the cells or sectors and a central transceiver. The base transceiver station acts as the interface between the telephone network and the wireless telephone system, and the central transceiver acts as the wireless telephone system interface with the broadband distribution network.
To carry wireless telephony signals over a broadband distribution network, as described above, a predetermined bandwidth on the network is typically allocated for this purpose. However, as required, more bandwidth may be allocated to carry wireless telephony signals. To most efficiently use a given bandwidth to carry wireless telephony signals between wireless telephones and the telephone network, a combination of frequency and time division multiplexing is utilized. This requires base transceiver station equipment that acts as the interface with the telephone network and the wireless telephone system. With the base transceiver station equipment is a central transceiver RASP), also called a Headend Interface Converter (HIC), that interfaces with the broadband distribution network, and it must function with telephony signals in the wide frequency spectrum of radio frequency signals on the telephone network, and up to 1000 Mhz over the broadband distribution network. This system also requires a plurality of remote transceivers, also called cable microcell integrators (CMI) or Remote Antenna Drivers (RADs), in each of the cells or sectors that can carry many channels of telephony signals between the wireless telephones and the central transceiver via the broadband distribution network, without creating signal interference with the telephony signals in adjacent cells or sectors. In addition, the remote transceivers (RADs) must function with and translate telephony signals in the wide frequency spectrums of up to 1000 Mhz on the broadband distribution network and between 1850-1990 MHz for the radio link between remote transceivers and wireless telephones.
The number of remote transceivers assigned to handle wireless telephone traffic in any given area depends on the normal level of telephone traffic experienced in the area. However, when normal traffic levels are exceeded some wireless telephone users experience busy indications and must wait to make a call.
Thus, there is a need in the art for a small, relatively inexpensive, remotely located transceiver that can be used in quantity in a wireless telephone system to carry telephony signals between wireless telephones and a central transceiver via a broadband distribution network, where operational parameters of the remote transceivers may be re-assigned to handle additional telephony traffic during peak traffic periods.
The above described need in the wireless telephone system prior art is satisfied by the present invention. A small, relatively inexpensive, remote transceiver is provided which is used in a wireless telephone system as briefly described above. These remote transceivers carry wireless telephone signals over a broadband distribution network, such as HFC, fiber optic cable, or coaxial cable, on which the transceivers are hung and to which they are connected, thus eliminating the need for antenna towers. Each remote transceiver is assigned to normally handle wireless telephone traffic in a small surrounding area, but the operational parameters of the remote transceivers can be dynamically changed from a central location so that each remote transceiver may be re-assigned to handle wireless telephony traffic from an adjacent area during peak traffic periods.